The Western astrological sign Cancer of the tropical zodiac (June 21 – July 22) differs from the astronomical constellation of Cancer and the Hindu astrological sign of the sidereal zodiac (July 21 – August 9).

In the tropical zodiac it represents the balmy expansiveness of mid summer. In the sidereal zodiac it is associated with the myth of the Lernaean Hydra, one of The Twelve Labours of Herakles.